Original Project
Energy: Forms, Transformation, Transfer, and Conservation
Item NG094002: Assuming no energy transfer between a ball and the track it is moving in, the amount of energy the ball has after it goes over a hill will be the same as before it went over the hill because the total amount of energy in the system did not change.
Imagine a ball on a track where no energy is transferred between the ball and the track or between the ball and the air around it. It is going fast enough at Position 1 so that it will go over a hill on the track and past Position 2. Position 1 and Position 2 are at the same height.
Will the total amount of energy the ball has at Position 2 be more, less, or the same as the total amount of energy the ball had at Position 1 and why? (Remember that no energy is transferred between the ball and the track or between the ball and the air around it.)
- The total amount of energy the ball has will be more at Position 2 because new energy was made when the ball went down the steep side of the hill.
- The total amount of energy the ball has will be less at Position 2 because energy was used up when the ball went up the long side of the hill.
- The total amount of energy the ball has will be the same at Position 1 and Position 2 because the total amount of energy in the system (ball and track) did not change.
- Whether the total amount of energy of the ball is more, less, or the same at Position 2 compared to Position 1 depends on the speed of the ball before it got to the hill.
- Distribution of Responses
- Students Responding Correctly
| Group | Correct | Total | Percent |
|---|---|---|---|
| Overall | 535 | 2320 | 23% |
| Grades | |||
| 6–8 | 265 | 1443 | 18% |
| 9–12 | 269 | 872 | 31% |
| Gender | |||
| Male | 267 | 1136 | 24% |
| Female | 258 | 1146 | 23% |
| Primary Language | |||
| English | 493 | 2098 | 23% |
| Other | 31 | 148 | 21% |